/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: fzykd
 * Date: 2023-05-11
 * Time: 16:20
 */

//屏幕
public class Screen {

    private static Screen instance = new Screen();

    public static Screen getInstance(){
        return instance;
    }

    public void up(){
        System.out.println(" screen up 屏幕上升");
    }

    public void down(){
        System.out.println("屏幕下降");
    }

}
